Sheet material punching apparatus



I Aug. 8, 1944. WALES 2,355,344

SHEET MATERIAL PUNGHING APPARATUS Filed Jan. 12, 1942' 5 Sheets-Sheet lHm, W; in

m 7; w m" @67 M INVENTOR.

BY W

ATTORNEYS SHEET MATERIAL PUNCHING APPARATUS Filed Jan. 12, 1942 3Sheets-Sheet 2 AT TOP/VEYS 1944. G. F WALES 2,355,344

SHEET MATERIAL PUNCHING APPARATUS Filed Jan. 12 1942 3 Sheets-Sheet 5 ZINVENTOR.

BY {W W; 6

AT TORNEYS' the same after it becomes dull.

Patented Aug. 8, 1944 UNITED STATES PATENT OFFICE snas'r MATERIALruuonme srrm'rus George F. Wales, Kenmore, N. r. Application January 12,1942, Serial No. 42am as Claims. 164-94) This invention relates to apunching apparatus which is more particularly intended for producing aplurality of closely spaced perforations in sheet material, such assheets of metal, and other articles, such as strips and angle bars whichform parts of aeroplane structures and the like, although this apparatusmay also be advantageously used for other work, particularly when thesame apparatus is used for perforating articles varying in thickness.

units embodying this invention may be assembled in a row close togetherfor producing rows of closely spaced openings in the workpiece.

Another object of this invention is to organize thespring means of thestripping mechanism so that the spring effect may be readily varied andthus permit of selectively adapting the power of the spring means of thestripping mechanism to suit the thickness or character of the metal fromoperation of perforating the same has been completed.

A further object of this invention is to provide simple and efllcientmeans for adjusting the die and punch of this perforating apparatus whenthe same are originally installed and also to take up forshortening ofthe punch due to sharpening A still further object of thisfinvention isto provide means whereby the individual members of a plurality ofpunching elements may be adjusted independently of each other as tolength and thus permit of great latitude in causing the several punchelements to effect their perforating operations either simultaneously orsuccessively in accordance with the thickness of the stock which isbeing perforated or to meet other conditions.

A punching apparatus of the general type to ance with the presentimprovements arranged side by side.

Fig. 3 is a top plan of one of the punching units containing the presentimprovements.

Fig. 4 is a horizontal section, taken on line |4, Fig. 1.

Figs. 5 and 6 are fragmentary views, similar to the upper part of Fig.1,showing various spring selections and arrangements to suit the opera- Ywhich the punches must be withdrawn after the which the presentinvention relates is shown in tions of punching and stripping sheetmetal which differs in thickness from that for which thespring means inFig. l is intended, and Fig. 6 also showing a diflerent form of springfor lifting the punch guide as compared with that shown in Figs. 1, 3, 4and 5.

Figs. 7, 8, 9 and 10 are fragmentary vertical sections showing variousforms of dies and means for adjusting the same in accordance with thisinvention which differ from that shown in Figs. 1, 2, 5 and 6.

Figs. 11, 12, "13, 14, 15, 16, 1'7, 18 and 19 are fragmentary verticalsections showing various forms of punches and means for adjusting thesame.

In the following description similar characters of reference indicatelike parts in the several figures of the drawings.

Referring to Figs. 1 and 2, the numeral i0 represents the lowersupporting bed or base which forms part of the main frame of thepunching press, press brake or the like and II the upper guide head ofthe same which has its rear part connected with the corresponding partof the bed by an upright arm or standard [2. 1 Above the bed is arrangeda ram 9 which may be guided on the frame head and reciprocatedvertically by any suitable means. Upon the bed of the frame is mounted atransverse horizontal supporting and guiding rail l3 which may beprovided with a longitudinal slot [4 registering with a similar slot I5in the bed. Upon this rail a plurality of punching 'unitsare mounted ina transverse row each of which units embodies the present invention andis constructed as follows: The numeral l6 indicates in general theholder which supports the various working parts of a punching unit andcomprises a lower die shoe I1, an upper punch head or horn l8 arrangedabove the shoe and spaced therefrom by a gap I9 and an upright standardor post20 connecting the rear parts of the shoe and horn, as shown inFig. 1. Each of these holders is comparatively narrow so that the samecan be arranged closely together in a row crosswise of the press topermit of producing rows of closely spaced openings in sheets of metal,although these holders may also be spaced comparatively far apart tosuit the requirements metal which are to be perforated. Although theseholders may be mounted in of the particular. sheets of plish this asfollows:

Each of the holders rests with its underside on the upper side of therail and provided on its underside with a longitudinal groove 2| whichreceives an upwardly projecting tenon or tongue 22. The holder when freecan be slid horizontally and transversely on the rail relative to theframe into the desired position but is held against fore and aftmovement by'cooperation of the tongue 22 and groove 2| formedrespectively on the rail and holder and after such adjustment the holdermay be secured in place by a vertical fastening screw bolt 23 passingthrough the front parts of the shoe and rail and provided at its upperend with a head 24 bearing against the top of the shoe and having aclamping nut 25 at its lower end which is arranged in a T-slot 26 formedin the front part of the rail.

Upon the shoe of each holder is. mounted a die and upon'the horn of therespective holder is mounted a vertically movable punch which cooperateswith said die for producing perforations in the sheet. material placedbetween the companion die and punch. The die shown in Figs. 1 and 2 hasan upright cylindrical body 21, the lower part of which is tightly heldby a driving or press fit in a cylindrical socket 28 in the respectiveholder shoe and the upper part'of which has a vertical die opening 29provided with a cutting edge 30 at its upper end and a slug dischargechute 3| extending from the lower end of the die opening laterally tothe periphery thereof.

"' For the purpose of positively'locating the upper end. of the die 21in the desired position when originally assembling the parts and also tocompensate forany reduction in its height when the upper end of the dieis resharpened after being worn dull, adjustable meaans are provided forsupporting or backing the die in its vertically adjusted position on theshoe. The vertically adjustable support'for this purpose may be variedbut those shown in Figs. 1 and 2 are satisfactory on account of theirsimplicity and the ease and convenience with which this adjustment maybe effected. As there shown these adjusting means comprise a verticallyadjustable abutment having the form of a screw plug 32 which works in aninternally screw threaded opening 33 forming a downward extension of thesocket 28. This screw plug is provided at its lower end with a non'circular recess 34 which is adapted to receive a wrench or other toolto turn the abutmerit screw 32 so that the same will either moveupwardly or downwardly and thus support the die either in a raised orlowered position as may be necessary for bringing the top of the dieinto the desired position. I

When it is desired to raise the die 21. afterthe upper end of the samehas been sharpened, or for any other reason, the holder is removed fromthe rail 13 and the supporting screw 32 is: removed and then the die ishit by means of a suitable'tool striking against its lower end untilthe-.die'has been moved upwardly the requisite distance after whichthebacking screw 32 is replaced and engaged tightly with the lower endof thedie. so as to support the latter firmly in its adjusted position.7

When effecting such adjustment of a die a snap gauge of well knownconstruction is used for resetting the die so that its upper end is inthe proper position, this gauge measuring the distance from the bottomof the holder to the face of the die and thus enable a plurality of suchunits to be maintained at the desired height.

When a. plurality of punching units aiemployed in the press and it isdesired that the I upper: ends or faces of the dies of the several unitsare on the same level or at different levels, the means for adjustingthe dies vertically makes this possible inasmuch as each die can beadjusted individually inqaccordance with the amount of material whichhas been removed upon sharpening the same when dull.

For convenience in perforating the flanges 35 of metal bars which areL-shaped in cross section and have beads or bulbs 36011 the inner sidesof these flanges, the die is provided below its upper end and oppositeits chute 3| with an undercut or recess 31 so that when one of theseflanges rests with its underside on the die, the bead or bulb on theother flange will project into the recess 31 and permit the respectiveflange to be perforated in the desired location relative to the cornerof the angular bar, as shown in Fig. l.

The numeral 55 represents the vertical body of the punch and 56 thecutting bit at the lower end of the body which is adapted to coope 'tewith the cutting edge of the die opening 29 f/the die for perforatingsheet material or other article which is placed between the die andpunch. The lower part of this punch body is guid 'd'in a guiding andstripping sleeve or tube 5T which slides vertically in a guide opening58 formed in the front part of the horn I8 of the "holder, as shown inFig. 1. At its lower end the guide sleeve 51 is provided with a reducedguide opening 59 for receiving the correspondingly reduced bit of thepunch. The punching, guiding and stripping sleeve or tube is yieldinglyheld in its elevated position by lifting means which in accordance withthe showing in Figs. 1, 3, 4 and 5 consist of a curved leaf-shapedspring 60 which is secured at its rear depressed end by a screw 6|, orotherwise, to the top of the horn l8 while its front elevated end 62 isforked so .as to straddle the guide tube 51 and bear against the centralparts of the underside of a longitudinally elongated head 63 arranged atthe upper end of the guide tube 51.

Depression of the punch is effected positively by the downward movementof the ram. 9 which operates on the upper end of the punch,

Means are provided for adjusting the overall or operative length of thepunch as a whole so as to properly locate the punch and bring the lowerend of the punch bit in line with the lower end of the guide sleeve, orsubstantially so, when the punch is in its uppermost position. For thispurpose adjusting means are provided for determim'ng the desired lengthof the punch when originally assembling the parts of the apparatus andalso restoring the length of the punch as a whole after the same hasbeen shortened by grinding the lower end for sharpening the samewhen-worn.

The specific means for lengthening or adjusting the length of the punchshown in Figs. 1, 2, 5 and 6 consist of a lower adjustable liftingscrew" nut 64 applied to the upper screw threaded end of the punch bodyand an upper clamping screw nut or head 35 arranged on the screw of thepunch body above the lifting nut. Spring means t are provided whichoperate on the underside of the lifting nut 64 and act to raise thepunch after each perforating operation so that the lower end of thepunch is flush, or substantially even, with the lower end of the guidesleeve 51 and thus permit the bit of the punch during its downward Aassessend of the stripper sleeve which strips the workmovement under thepressure of the descending wear and the total length of the same isshortened upon resharpening of the bit the length of the punch isrestored by loosening the clamping nut 65 and then unscrewing thelifting nut 64 until its underside is the required distance from thelower end of the bit after which the clamp-' ing nut is again tightenedfor holding the lifting nut in body.

The stripping means cooperate with the lifting spring 60 for removingthe work from the punch of the perforating unit after the punch haspierced the work, which stripping means, as shown in Figs. 1 to 6, areconstructed asfollows;

The numeral 85 representsan upper stripper head which is arranged abovethe lower lifting head 63 and the holder 26 and has the same blong formas this lower head, being comparative- 'plurality of punching units canbe assembled close together side by side crosswise of the press;

as shown in Fig. 2. At the front and rear ends of the lower lifting headand the upper stripper head 85 the same are connected respectively by 1ylong but narrower than the holder so that a I piece from the punch.During the downward \stroke of the mm the same engages the upper locknut or head 65 of the punch and moves the latter together with thestripper mechanism downward as a unit until the lower end of the itsadjusted position on the punch a linkage or loose connecting meansconsisting preferably of upright tie bolts 86, 8'! the-lower ends 88, 89of which are screw threaded and engage with threaded openings in thefront and rear ends of the lower lifting head 63 while the upper ends ofthese bolts slidably engage openings 96, 9| in the front and rear endsof the upper stripper head 85 and are provided respectively with heads92, 93 which engage with the upper side of the front and rear ends ofthe upper stripper head 85, as shown in Figs. 1, 5 and 6. The body 55 ofthe punch is arranged midway between the front and rear tie bolts 86,81. and is not connected with the bar or head 85 but is slidable withthat part thereof immediately below its lifting nut or member 64 througha non-threaded clearance opening '94 in the central part of the upperstripper head 85 and engages its lifting nut 64 with the upper side ofthis head, as shown in Figs. 1, 5 and 6, thereby permitting the punch tobe freely removed from the stripping means by merely lifting the sameout of the heads or bars 63, 85 and the sleeve 51. I

The numerals 95, 96 and 91 represent helical central, front and rearstripper springs which are interposed under an initial compressionbetween the lower lifting head 63 and the upper stripper head 85 andsurround, respectively, the body 55 of the punch and the from; and reartie bolts 86, 81. These springs are preferably of the same size andstrength and when the same are expanded to the extent permitted by thelinkage or tie bolts 86, 81, the stripper head 85 and lifting head 63are separated and the punch is lifted so that its lower or cutting endis flush with the lower end of the stripping and'guiding sleeve 51, or

substantially so.

when the ram 9 is iri'its highest position, as

stripper sleeve 5'! engages the upper side of the workpiece .resting onthe die after which the stripper sleeve ceases its downward movement butthe punch continues its downward movement and in cooperation 'withthedie punches a slug out of the workpiece and forms a hole therein whichslug passes downwardly through the opening in the die. During thisdownward movement of the stripper sleeve the lifting spring 68 isdeflected downwardly and during the downward movement of the punchindependently of the strippersleeve the stripper springs are furthercompressed. During the subsequent upward stroke of the ram the punchfirst moves upwardly with the same while the stripper sleeve remains atrestLami is held down by the strippersprings until the workpiece hasbeen stripped from the punch and then the stripper sleeve and punch arelifted from the workpiece and from the die by the lifting spring 60,thereby leaving a clearance space between the die and the punch andstripper sleeve to facilitate removal, of the finished workpiece and itsreplacement by another workpiece.

If the workpiece to be perforated is very heavy and requires much powerto strip the punch from the workpiece after the hole has been punchedtherein, then all three of the stripper springs 95, 96, 91 are employed,as shown in Fig. 1. If less power is required to strip the punch fromthe workpiece one of the strip'per'springs is omitted and for thispurpose the central spring 95 is removed in order to keep the springmeans of the stripper mechanism balanced. The removal of the centralspring 95 for' this purpose can be accomplished quickly and easily bywithdrawing the punch upwardly from the stripper sleeve 51 and the lowerand upper heads 63, and replacing the same after the central spring hasbeen removed, as shown in Fig. 6. If it is necessary to still furtherweaken the resistance of the stripper spring means, this can be done byemploying only one stripper spring and for this purpose the centralspring 95 is retained and the front and rear springs 96, 91 are omitted,so as to still balance the spring means of the stripping mechanism, asshown in Fig. 5. Removal of the front and rear springs 96, 91 for thispurpose can be easily effected by first detaching the tie bolts 86, 81from the upper and lower heads 65, 68 of the stripper mechanism. I

It will be noted that when changing of the central spring 95 from onesize or strength to a another is desired, this can be accomplished bymerely lifting the punch 55 out of its guideways in the upper head 85,lower head 63 and guide sleeve 51 whereby the spring, is wholly free tobe removed sidewise from between the heads 65 and 68 and thereafteranother spring of the desired strength may be substituted in the sameplace and the punch may beslipped through the.

corresponding guideways in the heads 85 and 68 and the sleeve 51 forrestoring the punching unit changeover.

of the punching apparatus while efiectingi this When punching a largenumber of holes in thick metal which requires more power than the presscan deliver,'it is common practice to grind the lengths of the punchestoprovide different times of penetration. When any punch contacts thematerial to be punched the working end of the punch penetrates into themetal an amount which depends upon the hardness of the metal before thepressure becomes too great for the metal to stand and at this pointtheslug breaks out of the metal and enters the die opening.

In mild steel this penetration is approximately one-third of thethickness. To illustrate: a punch will penetrate into three-sixteenthsof an inch thick mild steel approximately one-sixteenth of an inchbefore the slug breaks out of the workpiece.

In order to punch more holes than can normally'be punched with a givenpower every second punch may be ground one-sixteenth of an inch shorterthan its neighbor. Or the punches may be ground in steps over a greaterrange, for example, the first punch may be of full length, the secondone-sixteenth of an inch shorter, the third one-sixteenth of an inchshorter than the second, and the fourth one-sixteenth of an inch shorterthan the third.

It will therefore be aparent that the adjustability as to length of thepunches in accordance with this invention permits of great latitude inthis respect.

Means are provided for maintaining the strip ping mechanism in a positon in which its heads 83,,85 and row of springs 95, 96, 91 are arrangedin a vertical plane extending fore and aft of the press and thus renderthe punching unit comparatively narrow throughout its height to permitof assembling the same compactly transversely of the press. This ispreferably accomplished by means of a vertical pilot. or guide pin 98projecting downwardly from the lower end of the rear tie bolt 91 andsliding in a vertical guide opening 99 formed in the horn l8 in rear ofthe guide opening 58 for the stripping or guiding sleeve- 51. punch riseand fall the pilot pin 98 slides vertically in the guide opening butprevents the st ipping mechanism from turning laterally.

In the preferred construction the pilot pin of the spring elements foruse in the organization asmay be best suited for doing work of aparticular character. By making it possible to use different springpressures in the stripper mechanism, the press can be relieved fromdepressing more stripper springs or elements than are necessary forstripping the work in hand. This is of particular importance in the caseof apress in which several hundred punching units could be assembled-If, however, the press and the work in hand renders it impossible topunch, say 100 holes at the same time by the use of 800 strippersprings, then the spring resistance could be reduced one step byomitting the central stripper spring of each punching unit, making atotal of 100 springs which are cut out. If the work in hand is still tooheavy or the number of stripper units too great to permit of operatingthe press satisfactorily, then the resistance or pressure of thestripper spring means can be reduced another step by removing the frontand rear stripper springs from the several units, making a total of 200inactive springs. stripper springs to strip the work from the punchesdepends on a number of conditions, such as clearance between the punchand die of each unit, the kind of material which is being punched, andthe thickness of this material. It therefore may be necessary in doingwork of this character to punch fewer holes at one time if heavystripper spring pressure is required. The springs of the strippermechanism need only to be under suflicient compression while effectingthe punching operation to subsequently strip the work from the punch andthe latter only need be compressed enough togo through the work and thusmake it easy on the stripper springs.

Figs. '7 to 10 show various other ways for ad justing and backing up thedie to compensate for As the stripping mechanism and wear and sharpeningof the upper end of Working face of the same. In Fig. 7 the die 38 isprovided with a chute or discharge passage 42 which extends from the dieopening 29 at the upper end of the die to the lower end of the same andcommunicates with a central opening 39 in a, backing up or supportingscrew plug 40 working in a threaded opening 33 similar to theconstructions shown in Fig. 1. Upon turning the plug 40 passes throughan opening I00 in the leaf-shaped lifting spring 60 which latter has thefront edge |0| of its opening arranged so close to the front side of thepilot pin that the latter is gripped by this edge l0l during the lastpart of the upward movement of the lifting spring and acts like a clutchto limit the upward movement of the stripper mechanism and the punchduring the upward stroke of the ram. During the downward movement of thestripper mechanism with the ram and punch, the lifting spring isdepressed and flattened so as 'to disengage the gripping edge ml of thelifting spring from the pilot and thereby avoid interfering with thefree downward movement of the punch and stripper mechanism.

If-desired the stripper lifting spring may be of helical form, as'shownat I02 in Fig. 6, in which case this spring is placed around the pilotpin 98 and interposed between the underside of the lift- I permits ofselecting a smaller or greater number in the proper direction the samewill be raised for engaging the same with the lower end of the die andprovide a firm support or backing up for the die after the latter hasbeen sharpened and raised the requisite extent on the shoe of theholder. In this construction the slugs produced during the perforatingoperation pass downwardly through the die 38 and screw plug 40 to theunderside of the press instead of beingdischarged toward, the front sideof the press.

Instead of employing 'a screw plug for backing up or supporting the die,as shown in Figs. 1 and 7, the same result may be attained by fittingthe lower end of the die 4| in a vertical guide opening 42 in the shoel1 and backing up the die and v taking up for sharpening or wear bymeans of a screw nut 43 resting on the upper side of the shoe l1 andengaging with 'an external screw thread 44 on the die 4 I, as shown inFigs. 8 and 9. Fig. 8 shows the die 4| provided with a slug dischargechute 3I leading from the die opening 29 to the side of the die, asshown in Fig. 1, while in Fig. 9 the die 45 is provided with a slugdischarge chute 42l extending from the die opening 29 to the lower endof the die and through the lower part of the opening 42 to the undersideof the shoe l1.

The ability of the.

' said guide opening 41.

'tive position.

movable wedge rod 46 guided, in a guide opening.

41 in the shoe and provided with a bevel as at its inner end whichengages with a corresponding bevel 48 on the lower end of the die 58,and a screw nut or sleeve 5| journaled on the outer end of said wedgerod between two shoulders 62, 53 thereon and engaging its externalthread with an internal thread54 in the outer part of Upon turning thenut 5| in the proper direction the wedge rod 46 will be moved forengaging its bevel surfaces 48 with the bevel surface 48 of the die 58and thereby support the die in its proper position.

For the purpose of taking up for sharpening of the die by the meansshown in Fig. 10, after the face of the same has been ground on, thewedge rod 46 is first withdrawn by means of the screw in order to exposethe lower end of the die 50 and permit of hitting the same with a toolthrough the lower end of the guide opening 28 g and raising this die therequisite extent after which the wedge rod 46 is re-engaged with thelower end of the die 50 for supporting or backing the same properlywhile in use.

Equivalent means are shown in Figs. 11 to 19 for adjusting the overalllength of the punch and also the distance from the tip of its bit to itslifting surface. In Fig. 11 this is accomplished by means of a liftingscrew nut 66 applied to'the upper screw threaded end of the punch bodyand a clamping screw or set screw 61 working in the upper part of-thelifting screw nut 66 and engaging with the upper end of the punch body.Upon loosening the set screw plug 61 the lifting.-

screw nut 66 may be unscrewed sufllciently to obtain the requireddistance between the lifting face on the underside of this screw nut andthe lower end of the bit to compensate for the amount which has beenremoved from the bitfor sharpening purposes, after which the clampingscrew plug is again tightened to hold the nut 66 in place. I

' A like effect is obtainable by the construction which is shown in Fig.12 and which comprises a cap screw 68 applied to the upper screwthreadedend of the body '55 of the punch and a set screw or clamping screw 69working in a threaded opening in the side of this cap screw and providedwith a tapering inner end I0 which engages'with a correspondinglytapered upper end 1| on the" punch 'body. Upon loosening the set screwand turning the screw cap on the punch body, the distance between theunderside of the screw cap and the lower end of the punch may beincreased as much as required to maintain the lower end of the punchflush, when in its retracted position, with the underside of the guidesleeve, after which retightening of the set screw will hold therespective parts in their rela- The means for accomplishing this purposeshown in Fig. 13 consists of a screw cap 12 applied to the screwthreaded upper end 13 of the punch body 55 and one or more spacing oradjusting slugs or washers l4 interposed between 16 by a screw jointwith the punch body above this collar and placing a plurality of thinspacing or adjusting washers or slugs TI on the punch body underneaththis collar. Before the punch is worn at its lower end-all of thewashers 11 are placed on the punch body underneath the collar as shownin Fig. 14, so that the same will be supported on the upper head 85 ofthe stripping device, and as the lower end of the punch is ground oilfor sharpening it, some of the washers 11 are transferred from that partof the punch below the collar 15 to that part of the punch body abovethis collar and under- 1 neath the bearing ring 16, as shown in Fig. 15,

thereby lowering the punch on the upper head 85 of the stripping deviceto bring the lower cutting end of the punch in line, or substantiallyso, with the underside of the guide sleeve 51.

If desired the punch body may lbe provided at its upper end with an.extemally screw threaded collar I8 which is swaged thereto, aninternally threaded bearing cap 19 engaging 'with this threaded collar,and a plurality of movable washers 88 arranged on the punch bodyunderneath the threaded collar, as shown in Fig. 16. As the lower end ofthe punch is ground oil for sharpening the same the punch is lowered bytransferring washers from the punch body underneath the threaded collar18 to the space between the upper side of this collar and the top of thescrew cap 18, as shown in Fig. 17, thereby compensating for the stockremoved from the cutting bit of the punch.

According to the construction 18 and 19, a collar 8| of the punch bodyby swaging or otherwise, a thick ring 82 is adjustably secured to theupper end of the punch body by a set screw 83 and a plurality of thinadjusting washers 84 are mounted on the punch body below said collar.When the punch is first mounted the thick ring 82 is placed on the punchbody immediately above the collar 8| and all the washers are placed onthe punch body below the collar, as shown in Fig. 18. As the wear on thelower end of the punch bit necessitates sharpening and consequentshortening of the same, the punch body shown in Figs.

is lowered as a whole by transferring washers 84 the upper end of thepunch body and the top from that part of the punch body 'below thecollar 8| to that part of the body between the top of the collar and thebearing ring 82, as shown in Fig. 19.

All of the several means for adjusting the overallglength of the punchhere shown are very simpl in construction, the same can be manipulatedeasily and quickly and they are of sturdy construction and not liable toget out of order under heavy duty.

In the several forms of this invention whereby the overall length of thepunch, and particu-' larly the distance from its lower cutting edge toits lifting surface may be adjusted the several parts whereby thisadjustment is eifected, when taken as a whole, may be regarded as abearing or lifting head or element and is so taken in the wording of theappended claims.

'It will be noted from the drawings that the holder of each perforatingunit is made very narrow throughout its height and that the severalparts of the die, punch and stripping means associated therewith arealso made correspondingly narrow and do not project laterally beyond theoutline of the holder, thereby enabling a plurality of such perforatingunits to be assembled close together in a transverse row and is securedto the upperpart movable lengthwise thereon, a normally stationary diemember mounted on said holder, a punch 1 member movably mounted on saidholder and adapted to be moved by said ram toward said die member andthe workpiece to be perforated, resilient means for moving said punchaway from said die and the workpiece, and adjusting means for adjustingthe relative position of said die -and punch members for bringing theircooperating parts in the proper cooperating position with other likeunits independently of said bed and ram. *2

2. In a'press having a bed and a ram movable toward and from the bed,multiple perforating units, each of said units comprising a holder whichis adjutably mounted on said bed and movable lengthwise thereon, anormally stationary die member mounted on said holde a punch membermovably mounted on said holder and adapted to be moved by said ramtoward said die member and the workpiece to be perforated, [resilientmeans for moving said punch away from said die and the workpiece, andadjusting means for adjusting the relative position of said die andpunch members for bringing their cooperating parts in the propercooperating position with other like units independently of said had andram, said adjusting means-including a screw mounted on said holder andadapted to bear against said die member and move the same toward saidpunchmember.

3. In a press having a bed and a ram movable toward and from the bed;multiple perforating units, each of said units comprising a holderwhichis adjustably mounted on said bed and movable lengthwise thereon, anormally stationary die member mounted on said holder, a punch membermovably mounted on said holder and adapted 'to be moved by said ramtoward said die member and the workpiece to be perforated,

resilient means for moving said punch away from said die and theworkpiece, and adjusting means for adjusting the relative position ofsaid die and punch members for bringing their cooperating parts in theproper cooperating position with other like units independently of saidbed and ram, said adjusting means including a screw nut resting on saidholder and having a thread connection with said die member whereby thelatter will be moved toward said punch member upon turning said screwnut in the proper direction.

4. In a press having a \bed and a ram movable toward and from the bed,multiple perforating units, each of said units comprising a holder whichis adjustably mounted on said bed and movable lengthwise thereon, anormally stationary die member mounted on said holder, a punch membermovably mounted on said holder and adapted to be moved by said ramtoward said die member and the workpiece to be perforated, resilientmeans for moving said punch away from said die and the workplace, andadjusting means for adjusting the relative position of said die andpunch members for bringing their coop! crating parts in the propercooperating position with-other like units independently of said bed andram, said adjusting means including a wedg slidablymounted on saidholder and engaging said die member whereby said die member will bemoved toward said punch member upon moving the wedge in the properdirection.

5. In a press having a bed and a ram movable toward and from the bed,multiple perforating units, each of said units comprising a holder whichis adjustably mounted on said bed and movable lengthwise thereon, anormally stationary die member mounted on said holder, a punch membermovably mounted on said holder and adapted to be moved by said ramtoward said die member and the workpiece to be perforated, resilientmeans for-moving said punch away from said die and the workpiece, andadjusting means for adjusting the relative position of said die andpunch members for bringing their cooperating parts in the propercooperating position with other like units independently of said bed andram, said adjusting means including a head adjustable lengthwise on saidpunch member and and adapted to be shifted between said collar said dieand the workpiece, and

adapted to be engaged by said ram.

6. In a press having a :bed and a ram toward and from the bed, multipleperforating units, each of said units comprising a holder which isadjustably mounted on said bed and movable lengthwise thereon, anormally stationary die member mounted on said holder, a punch membermovably mounted on said holder and adapted to be moved by said ramtoward said die member and the workpiece to be perforated, resilientmeans for moving said punch away from adjusting means for adjusting therelative position of said die and punch members for bringing theircooperating parts in the proper cooperating position with other likeunits independently of said bed and ram, said adjusting means includinga collar fixed on said punch member, a'bearing head above said collarand adapted to be engaged by said ram, and washers adapted to be mountedon said punch member below said collar and to be shifted between saidcollar and bearing head 7. A perforating unit for use in connection witha press having a bed and a ram movable toward and from thebed, saidperforating unit comprising a holder which is independent of said bedand ram and supported on said bed, a normally stationary die membermounted on said holder, a punch member movably mounted on said holderand adapted to be moved by said ram toward said die member and theworkpiece to be perforated, resilient means for moving said punchawayfrom said die and the workpiece, and adjusting means for adjusting therelative position of said die and punch members for bringing theircooperatin parts in the proper cooperating position independently ofsaid bed and ram, said adjusting means including a collar fixed on saidpunch member, a bearing head having a screw connection with said collarand adapted to be engaged by said ram, and washers mounted on the punchmember below said collar and bearing head.

8. A perforating apparatus including a bed, a

ram movable toward and from the bed, and a plurality of perforatingunits each of which compri wit a socket, a die adjustable lengthwise insaid socket for changing the position of the'face of movable a holderresting on the bed and provided the die, thread controlled means forretaining gaged by said'ram for moving the punch toward said die.

9. A perforating apparatus comprising a bolster, a plurality of unitaryperforating units mounted in a row on said bolster and each unitincluding a punch and a die which are movable one toward and from theother for perforating and releasing a workpiece, and means foradju'sting the relative position of the punch and die of each unit sothat the working place at which the cutting edges of the same cooperatemay be maintained at a predetermined location and the working places ofthe punches and dies of the several perforating units may be allmaintained in the desired relation 'to' avoid distorting the workpiecewhen punching and stripping pressure is applied thereto.

10. A hole punching device, comprising a unitary holder having a lowerbase and upper head, a perforating die mounted on said base, a punchingand multiple spring stripping unit mounted and guided on said head andhaving at least one spring held in position by the punch in such mannerthat said spring may be removedor replaced by lifting said punch topermit such change. Y

v 11. A hole punching device, comprising a unitary holder having a lowerbase and upper head, a perforating die mounted on said base, a punchingand multiple spring stripping unit mounted and guided on said head insuch manner that the punching unit may be freely lifted from said upperhead so that one of the plurality of pressure elements may be added toor removed from said unit.

12. In a punching apparatus for use between the bed and ram of a press,comprising a holder havin a lower base and an upper head, a perforatingdie mounted on said base, a punching device mounted and guided on saidhead as a punching unit, means for preventing said punching device fromturning about on its axis including a pin extending downwardly from alateral portion of said device and engaging said upper head.

13. In a punching apparatus for use between the bed and ram of a press,comprising a holder having a lower base and an upper head, a perforatingdie mounted on said base, a punching device mounted and guided on saidhead as a punching unit, means for preventing said punchin device fromturning about its axis including a pin extending downwardly from alateral portion of said device and engaging said upper head, and meansfor yieldingly maintaining said device in an elevated position when notengaged by said ram including resilient means interposed between saiddevice and said upper head.

14. 1n a punching apparatus for use between the bed and ram of a press,comprising a holder having a lower base and an upper head, a perforatingdie mounted on said base, a punching device mounted and guided on saidhead as a punching unit, means for preventing said punching device fromturning about its axis including a pin extendin downwardly from alateral portion of said device and engaging said upper head, and meansfor yieldingly maintaining said device an elevated position when notengaged by said ram including resilient means interposed between saiddevice and said upper head and surrounding said pin.

, 7 15. Ina pum .iing apparatus for use between the bed and ram of apress, comprising a. holder having a lower'base and an upper head, aperforating die mounted on said base, a punching devicemounted andguided on said head as a punching unit, means for preventing saidpunching device from turning about'its axis including a pin extendingdownwardly from a lateral portion of said device and engaging said upperhead, and means for yieldingly maintaining said device in an elevatedposition when not engaged by said ram comprising a leaf spring attachedto said upper head and bearing upwardly on said device.

16. In a pun'chingapparatus for use between the bed and ram of a press,comprising a holder having a lower base and an upper head, aperforatingdie mounted on said base, a punching device mounted and guided on saidhead as a punching unit, means for preventing said punching device fromturning about its axis including a pin extending downwardly from alateral portion of said device and engaging said upper head, means foryieldingly maintaining said device in an elevated position when notengagedby said ram comprising a leaf spring attached to said upper headand bearing upwardly on said device, and means for preventing theaccidental separation of said device from said head comprising anopening in said leaf spring through which said pin projects, whichopening is positioned to cause said spring to seize said pin when the desired elevation of. said punchin device has been reached and thus limitthe upward movement of the same.

17. In a punching apparatus for use between the bed and ram of a press,comprising aholder V having a lower base and an upper head, aperforating die mounted on said base, afloating punch guiding andstripping device including a sleeve the outer diameter of which slidablyengages an opening in said upper head concentricwith said die and saidsleeve having an opening which slidably engages a punch and guides theworking end of the same die, and means for applying to said sleeve 9.resilient elevating eifect, resilient punch stripping effect, and antirevolving effect.

18. In a punching apparatus for use between the bed and ram of a press,comprising a holder having a lower base and an upper horn, a perforatingdie mounted on said base, a floating punch device including an upperbearing head, a sleeve slidably engaging its periphery with an openingin said upper horn, the interior of said sleeve slidably receiving apunch and guiding the working end ofthe latter concentrically into saiddie, and means for applying to said sleeve resilient elevating means,said sleeve being provided with a longitudinally extending lower head,resilient punch stripping means bearing on and interposed between thelower head and the upper bearing head, means for slidably connectingsaid upper head and said lower head, said upper head being provided witha punch accommodating opening in concentric relation with the opening insaid punch guiding sleeve and a punch comprising a working end,

a a body, and an enlargement, said working end and body being guided insaid sleeve and said enlargement bearing freely against the upper concentrically into said .punchworkin .19. In a punching apparatus for usebetween v the bed and ram of a press, comprising a holder an upper horn,a perhaving a lower base and forating die mounted on said base, an upperbearing head, a floating punch guiding and strip ping device including asleeve slidable with its periphery in an opening in said horn andadapted to slidably receive on'its interior a punch the working end ofwhich is concentric with said die, resilient elevating means applied tosaid sleeve, said sleeve being provided with a longitudinally extendinglower head, resilient punch stripping means interposedbetween the, topof said lower head and the upper bearing head, means for slidablyconnecting said upper head and lower head, said upper head being;provided with a punch accommodating opening in concentric relation withthe opening said punch guiding sleeve, and a punch comprising a workingend, body and enlargement, said working end and body being guided insaid sleeve and said enlargement bearing freely against the upper faceof said upper head to retain said end inside of said sleeve except whensaid ram depresses said working end into the material being worked upon,and means for preventing said device from revolving about its axis.

20. In a device comprising punch and stripper, means for restoring theover-all length of a punch, as .a whole, after the samehas beenshortened by grinding, said means being confined to the punch, its headand adjustments so as to maintain the cutting edge of the punch incorrect relation to the stripper.

21. In a device comprising punch and stripper, means for restoring theoverall length of a punch, as a whole, after thesame has been shortenedby grinding, said means being confined to the punch bit, unch body, headand adjustment so' as to maintain the cutting edge of the punch incorrect relation to thestripper.

22. In a device comprising punch and stripper, means for adjusting theover-all length of a much, as a whole, and within itself, comprising apunch body, an adjustable head and means for locking said head in itsdesired position so as to maintain the cutting edge of the punch incorrect relation to the stripper.

' 23. A erforating apparatus according to claim 19 containing' means forrestoring the over-all length of the punch as a whole after the same hasbeen shortened by grinding, including a punch body, an adjustable head,and'means for locking said head in its desired position on said body.

2.4. The herein described method of maintaining inverticalrelativepostions the cutting faces of the cutting elements of aplurality of perforating devices, each of which is a complete unitindependent of other like units and has a die element and a punchelement cooperating with the die element, said method consisting ofplacing any one of said die elements in its unit with its cutting facein the desiredhorizontal relation to the cutting faces of other dieelements in other units, locking said elements in said position andadjusting the overall length of said punch element to cooperate properlywith said die element.

25. The herein described method of maintaining in horizontally alinedpositions the cutting faces of the cutting elements of a plurality ofperforating devices, each of which is a complete unit independent ofother like units and has a die and a punch cooperating with the die,said method consisting in adjusting the overall length of any one ofsaid punch elements to plac its cutting face in the desired horizontalposition relative to the cutting faces of other punch elements in theother units.

26. A perforating apparatus comprising a holder, a die mounted on thelower part of said holder, a vertically movable punch mounted on theupper part of said holder, and stripping means including a plurality ofresilient elements in a retainer arranged above said upper part wherebythe punch is stripped from the 'workpiece and which is capable ofvariation in capacity by changing the number of springs in saidcontainer for adapting the stripping means to varying conditions.

27; A perforating appa'iatus comprising a holder, a die mounted on thelower part of said holder, a vertically movable punch mounted on theupper part of said holder, and means for stripping said punch from theworkpiece including a plurality of springs in a floating punch carrierabove said upper part, the number of which may be selected to suitvaryingconditions.

28. A perforating apparatus comprising a holder, a die mounted on thelower part of said holder, a vertically movable punch mounted on theupper partof said holder, and means for stripping the punch from theworkpiece includ- 1 ing a stripper sleeve which receives the lower tweenthe stripper sleeve and said member and capable of being selected as ton'umber for varying the stripping pressure to suit varying conditions.

29. A perforating apparatus comprising a holder, a die mounted on thelower part of said holder, a vertically. movable punch mounted ontheupper part of said holder, and means for stripping the punch from'theworkpiece including a stripper sleeve which receives the lower part ofsaid punch and which is guided on the upper part of the holder, alifting member which receives the upper part of said punch, a pluralityof stripper springs arranged between the stripper sleeve and said memberand capable of being selected as to number for varying the strippingpressure to suit varying conditions, and tie means connecting saidstripper sleeve and lifting member and operating to limit I theseparation of the same.

30. A perforating apparatus comprising a holder, a die mounted on thelower part. of said holder, a vertically movable punch mounted on theupper part of said holder, and means for stripping the punch from theworkpiece including a lifting member arranged on the upper part of saidpunch, a stripper sleeve which receives the lower part of said punch andis guided for vertical movement on the upper part of said holder, atlower head secured to said stripper sleeve, an upper head slidable onthe punch and engaging with the lifting element thereon, tie membersarranged on opposite sides of said punch and each connected at one endto one of said heads,' and slidable at its opposite end on the. otherhead, and spring surrounding said punch and tie members and interposedbetween said heads.

31. A perforating apparatus comprising a holder, a die mounted on thelower part of said I above the die and holder, a vertically movablepunch mounted on the upper part of said holder, and means for strippingthe punch from the workpiece includ ing a lifting member arranged on theupper part of said unch, a stripper sleeve which receives the lower partof said punch and is guided for vertical movement on the upper part ofsaid holder, a lower head secured to said stripper sleeve, an upper headslidable on the punch and engaging with the lifting element thereon,

upright tie bolts arranged on opposite sides of said punch and eachhaving a screw connection between its lower end and said lower head andhaving its upper end sliding on said upper; head .and provided with astop engaging with the upper side of said upper head, and helicalsprings surrounding said punch and tie bolts and interposed between saidlower and upper heads.

32. A perforating apparatus comprising aholder, a die mounted on thelower part of the holder, a vertically movable punch arrangedcooperating with the latter, and stripping mechanism for removing thepunch from th perforated workpiece including a stripping sleeve whichreceives the lower part of said punch and is slidable on the upper partof said holder, a lower oblong head arranged on the upper end of saidsleeve, an upper oblong head slidable on said punch andoperativelyengaging a lifting member thereon, said heads being parallel lengthwisewith each other and with said holder, spring means interposed betweensaid heads and holding them yieldingly apart, tie means connecting saidheads and limiting their separation, and pilot means which permitvertical movement of said heads and sleeve same.

er, a die mounted on the lower part of the holder, a 'vertically movablepunch arranged above the die and cooperating with the latter, andstripping mechanism for removing the punch from the perforated workpieceincluding a stripping sleeve which receives the lower part of said punchand is slidable on the upper part of said holder, a lower oblong headarranged on the upper end of said sleeve, an upper oblong head slidableon said punch and operatively engaging a lifting member thereon, saidheads being parallel lengthwise with each other and with said holder,spring means interposed between said heads and holding them yieldingiyapart, tie means connecting said head and limiting their separation, andpilot means which'permit vertical movement of said heads and sleeve butprevent horizontal turning of the same, said pilot means including avertical pilot pin projecting downwardly from a member of the tie means,and a guide opening arranged in the upper part of said holder andreceiving said pilot pin. l v a 34. A perforating apparatus comprising aholder, a die mounted on the lower part of said holder, averticallymovable punch cooperating with said die, and stripping meansabove said holder for removing the punch from the perforated workpieceincluding a tubular stripping sleeve which receives said punch andisguided on the upper part of said holder, and resilient 33. Aperforating apparatus comprising a holdbut prevent horizontal turning ofthe lifting, means which operate to raise the stripper sleeve and alsolimit the upward movement of the same.

35. A perforating apparatus comprising a holder, a die mounted on thelower part of said holder, a vertically movable unch cooperating withsaid die, and stripping means for removing the punch. from theperforated workpiece including a stripping sleeve which receives saidpunch and is guided on holder, a head arranged on the upper end of saidsleeve, stripper spring means interposed between said head and the upperpart of said punch, a pilot pin projecting downwardly from said head andslidable in an opening in the upper part of said holder, and aleaf-shaped lifting spring secured at one end to said holder andprovided at its other end with a fork which holder, ahead arranged onthe upper end of said sleeve, stripper spring means interposed betweensaid head and the upper part of said punch, a pilot pin projectingdownwardly from said head and slidable in an opening in the upper partof said holder, and a leaf-shaped lifting spring secured at one end tosaid holder and provided at its other end with a fork which straddlessaid sleeve and bears against the underside of said head and saidlifting spring being also provided with an opening which receives saidpilot pin, and an edge of said opening being arranged to engage saidpilot pin for arresting the upward movement of the same and the partsconnected therewith.

37. An apparatus for perforating the flanges of a bar which is ofangular form in cross section and which is rovided on the inner side ofone of its ,flanges with a bead, comprising a die provided below itsface with a recess for receiving the bead of the respective flange whilethe other flange of the same rests on the face of the adapted toperforate the last mentioned flange.

38. An apparatus for perforating the flanges of a bar which is tion andwhich is provided on the inner side of one of its flanges with a bead,comprising a die provided with a bearing face, a longitudinal openingforming a cutting edge on said face, a discharge chute extendinglaterally from said opening to the side of the die, and an undercut orrecess formed on the die below its face and opposite the outer side ofsaid chute, and a punch adapted to cooperate with the opening andcutting edge of said die, the face of said die being adapted to supportone flange of said bar while the same is being perforated between theupper part of said of angular form in cross sec-

